Dumnarth II of Cornwall

Dumnarth II of Cornwall (830-876), also known as Donyarth, Doniert, or Dungarth, was the king of Cornwall from 865 to 876, succeeding Ferverdyn of Cornwall.

Biography
Dumnarth was born to the House of Cerneu scion Ferverdyn of Cornwall, and was a Christian. Dumnarth succeeded his father as King of Cornwall on his death in 865, and reigned until he died in 876 of drowning in the River Fowey near King Doniert's Stone.